The Peptide Functionalized Inorganic Nanoparticles for Cancer-Related Bioanalytical and Biomedical Applications.

In order to improve their bioapplications, inorganic nanoparticles (NPs) are usually functionalized with specific biomolecules. Peptides with short amino acid sequences have attracted great attention in the NP functionalization since they are easy to be synthesized on a large scale by the automatic synthesizer and can integrate various functionalities including specific biorecognition and therapeutic function into one sequence. Conjugation of peptides with NPs can generate novel theranostic/drug delivery nanosystems with active tumor targeting ability and efficient nanosensing platforms for sensitive detection of various analytes, such as heavy metallic ions and biomarkers. Massive studies demonstrate that applications of the peptide-NP bioconjugates can help to achieve the precise diagnosis and therapy of diseases. In particular, the peptide-NP bioconjugates show tremendous potential for development of effective anti-tumor nanomedicines. This review provides an overview of the effects of properties of peptide functionalized NPs on precise diagnostics and therapy of cancers through summarizing the recent publications on the applications of peptide-NP bioconjugates for biomarkers (antigens and enzymes) and carcinogens (e.g., heavy metallic ions) detection, drug delivery, and imaging-guided therapy. The current challenges and future prospects of the subject are also discussed.

Enzyme activity termination by titanium carbide nanosheet and its application for the detection of deoxyribonuclease I.

Deoxyribonuclease I (DNase I) is a typical nuclease that plays key roles in many physiological processes and the development of a novel biosensing strategy for DNase I detection is of fundamental significance. In this study, a fluorescence biosensing nanoplatform based on a two-dimensional (2D) titanium carbide (Ti3C2) nanosheet for sensitive and specific detection of DNase I was reported. Fluorophore-labeled single-stranded DNA (ssDNA) can be spontaneously and selectively adsorbed on Ti3C2 nanosheet through the hydrogen bond and metal chelate interaction between phosphate groups of ssDNA and titanium of Ti3C2 nanosheet, resulting in effective quenching of the fluorescence emitted by fluorophore. Notably, it was found the enzyme activity of DNase I will be terminated by the Ti3C2 nanosheet. Therefore, the fluorophore-labeled ssDNA was firstly digested by DNase I and the "post-mixing" strategy of Ti3C2 nanosheet was chosen to evaluate the enzyme activity of DNase I, which provided the possibility of improving the accuracy of the biosensing method. Experimental results demonstrated that this method can be utilized for quantitative analysis of DNase I activity and exhibited a low detection limit of 0.16 U/ml. Additionally, the evaluation of DNase I activity in human serum samples and the screening of inhibitors with this developed biosensing strategy were successfully realized, implying that it has high potential as a promising nanoplatform for nuclease analysis in bioanalytical and biomedical fields.